Electromagnetically<?Pub Caret?> induced transparency with nuclear spin

Abstract

We report the observation of electromagnetically induced transparency in a sample of cryogenically cooled ground-state atomic ytterbium ((1)S(0)). The transparency is produced due to coherence between the optical field and the nuclear spin state of the (173)Yb nucleus. Because the nuclear spin states interact very weakly with their environment, they are resistant to decoherence due to inelastic collisions and inhomogenous fields. Consequently, atomic ensembles of pure nuclear spin states may be a superior medium for a variety of nonlinear optics and quantum information experiments.

Electromagnetically induced transparency in an open multilevel system

“…We produce Yb by laser ablation of a solid target, and cool it to 5 Kelvin via cryogenic helium buffer-gas cooling, as described in references [21,22].…”

Stopped light with a cryogenic ensemble ofYb173atoms

“…We use electromagnetically induced transparency to create a dark-state polariton [1,9] using the nuclear spin of ground-state 173 Yb (I = 5/2). We optically pump the nuclear spin of 173 Yb and create the dark state using the 6s 2 1 S 0 (F = 5/2) → 6s6p 1 P o 1 (F = 5/2) transition at 399 nm [10], illustrated in Fig. 1.…”

“…ablation of a solid ytterbium target inside a 10-cm cubic copper cell filled with a helium buffer gas. The helium cools the ytterbium atoms to a translational temperature of 4 K on a time scale of a few hundred microseconds, and the ytterbium slowly diffuses through the helium to the cell walls where it adsorbs [10,12].…”

“…The pulse's spectral width is chosen to be smaller than the electromagnetically induced transparency linewidth EIT [10], and as a result of the narrow EIT window, the signal pulse propagates with a slow group velocity [17,18]. The resulting delay can be seen in Fig.…”

“…We attribute this decrease to off-resonance absorption by the other Yb isotopes. The dominant broadening mechanisms in our experiment, as determined from a Voigt multipeak fit to our absorption spectrum, are Doppler broadening (FWHM 8 × 10 7 Hz at 4 K) and pressure broadening [(1.7 ± 0.2) × 10 −19 GHz/cm −3 [10]]. At n He = 3 × 10 17 cm −3 , the optical density from the I = 0 ytterbium isotopes is 0.3 of the D 0 of 173 Yb.…”